Posted
by
Soulskillon Friday August 19, 2011 @08:43AM
from the one-one-two-three-five-eureka dept.

An anonymous reader tips news of 7th grader Aidan Dwyer, who used phyllotaxis — the way leaves are arranged on plant stems in nature — as inspiration to arrange an array of solar panels in a way that generates 20-50% more energy than a uniform, flat panel array. Aidan wrote,
"I designed and built my own test model, copying the Fibonacci pattern of an oak tree. I studied my results with the compass tool and figured out the branch angles. The pattern was about 137 degrees and the Fibonacci sequence was 2/5. Then I built a model using this pattern from PVC tubing. In place of leaves, I used PV solar panels hooked up in series that produced up to 1/2 volt, so the peak output of the model was 5 volts. The entire design copied the pattern of an oak tree as closely as possible. ... The Fibonacci tree design performed better than the flat-panel model. The tree design made 20% more electricity and collected 2 1/2 more hours of sunlight during the day. But the most interesting results were in December, when the Sun was at its lowest point in the sky. The tree design made 50% more electricity, and the collection time of sunlight was up to 50% longer!"His work earned him a Young Naturalist Award from the American Museum of Natural History and a provisional patent on the design.

Actually, not really, no. If it was this obvious, he wouldn't be the first guy to think of this in 30 years to think of it.
Think of it this way: a patent on practical nuclear fusion will not be denied because the stars came up with it first.

That does look like prior _art_, but not like prior _science_. The Fibonacci-tree is not about some random and good-looking arrangement of the solar panels to make a cool gadget to charge your iphone. It is about the exact, calculated arrangement of those panels to increase the efficiency.

We had a course in 2003, where we had to use a few panels to provide electricity for a specific device we where to built. We were made well aware that a static orientation toward the mean would be the easiest to built, but the less performing one, that a tracking device power would eat quite a chunk of the extra electricity we would be generating, and that we could explore tons of other orientations, even to get our inspiration from the trees.

Uh, that's a nice picture but there's a lot more to what the kid did than make a diorama of a tree and glue solar panels to it instead of leaves. What you posted is a nice looking pic but there is no additional info. As far as I can tell, it's just an ipod/iphone solar charger with an aesthetically pleasing design. Is there anything to suggest that the designers of the charger in the pic thought to reproduce the phyllotaxis as a way of increasing efficiency? That's the, potentially, patentable part about the kid's work, not the fact that he made it "look like a tree".

No. For example, Robert Heinlein first described the waterbed in Stranger in a Strange Land and therefore, patents were denied to other people because his description was already there in the public domain. Of course, he couldn't have later patented it either, for the very same reason.

The reason nobody patented it before is that it is NOT actually more efficient and the production setup is overly complex for the job. Read my analysis above.

His "power gain" is due to using crappy PV cells that maxed out overly fast in direct sun. Rerun the experiment with PV cells that didn't max out ("clipping") and abandon potential power and you'd have a different result.

Now, the fact that he had a longer power arrangement isn't that hard to do either. Want to make something to function in a similar wa

Nature was first, but he is not patenting it as nature provides (something that can't be said for bug Pharma and DNA). While he is using the same general concept as provided by nature he adapted it to use solar panels and other materials not in nature. There are plenty of things that should be obvious, but for various reasons are overlooked or discounted before they are even shared.

Small nitpick - nature will optimize to a local minimum but not necessarily the global minimum. i.e. the plants might be stuck with the 'good enough' design instead of the fully optimized version. In this case, it appears that the 'natural' solution is pretty good and well optimized, especially with the low fluence case (i.e. the winter).

It's a minor but important nitpick because not all plants use the same spread and angles - I haven't read up on this, but it implies to me that there area niches in an ecosystem to have other solutions (kind of like the scavengers around the top predator - the predator might be really successful at getting it's food, but there might still be meat on the bone for the scavenger birds.) To bring the analogy back to topic, there might be other spacing/angle solutions that, alone, are worse, but with a secondary system placed interstitially, result in an overall more efficient solution. (Barely-thought about examples: placing a reflective base below, and having two-sided panels to catch other angles - or, perhaps studying the placement and angles of vine leaves can give an interstitial solution.)

So, locally minimized solutions can still be great, especially if a second-order approach cleans it up even further (as in the natural example.)

I believe trees for the most part lose their leaves because water freezes in winter and this would make it difficult to keep nutrients flowing to the leaves. Nature has established a balancing act based on the needs of a particular species in a given geographical context. What is being balanced will vary. It is not all about solar input in plants.

For the solar panels it could be a heat issue. I remember reading a few months back that solar panel efficiencies drop when it gets too hot. Here is one article ma

I don't think you realize exactly what you're saying here. You might not be from America, where the school system is a bit different from elsewhere. Here, children start 1st grade at age 6 to 7, and continue through elementary school (grades 1 through 6), junior high or middle school (grades 7 and 8), and high school (grades 9 through 12).

That's the same as where I grew up, except for junior high lasting until 9th grade, and high school being three years.

So, this 7th grader is, in fact, aged at 13 or 14 years old, and so I would like to politely challenge you to point out a recent period at which he would have been considered an adult.

My paternal grandfather started working as a carpenter apprentice when he finished obligatory school (7th grade), and got married a couple of years later. I've never known a man who knew more maths and geometry than him - that was back when they taught these things to children, not to young adults.My maternal grandfather became a fisherman at age 13, a sailor at age 15, and was a pilot by t

Evolution make no claims of producing optimal setups - for a single component or for the whole.

There are also likely plenty of other selection pressures on plants that have to be traded off against solar energy collection.

But yes it does seem like something someone would have tried before - then again putting your solar panels where there they aren't in shade at any point and pointing them at the same should still be better. Of course for solar panels not in the middle of the desert that can be problematic.

Somehow I doubt that the American Museum of Natural History missed that, after reviewing him for a rather prestigious award for someone his age. There's most probably something we can't see from the picture alone, or the discrepancy was accounted for in the math.

What seems to count for this award is a scientific investigation driven by a well-posed question. He did just that -- he tested a hypothesis by making a setup, doing repeated measurements, and drawing conclusions. Awards such as these want to encourage exactly what this boy has done. That he made a basic mistake in his setup is probably simply not all that relevant.

Um something something and your high horse... Nobody's coddling the kid here. If you actually read the article you'll see he's thought through all the points this thread has made. They're not just rewarding him for effort, but for an actually useful find.

The article is just his personal explanation of his experiment. Not why they rewarded him or whether the results are actually useful in practice. The 'about the award' page gives the impression that it's about the scientific process and encouraging inquiring minds. Neither could I find anything about cell count in the tree versus the array in the text, or about the average elevation of both models.

You can't see the back side of the flat array. I bet there's another ten on the other side. I also think there are probably 20 on the tree, not 18. I can't see the whole tree clearly enough to get an accurate count. It seems to me that a young man smart enough to work out a design like this would not overlook something so simple as the number of cells in use during his experiment and I'm willing to give him the benefit of the doubt when the only proof against him is a single incomplete photo.

You can't see the back side of the flat array. I bet there's another ten on the other side

OK, that may be true. But then those 10 'north facing' cells are pretty useless and could probably be removed without actually affecting energy production. How many people install (in the northern hemisphere) panels that are north-facing?

How many people install (in the northern hemisphere) panels that are north-facing?

I hear it's a popular practice in the southern hemisphere:)

But I agree - the total area of the solar panels on the tree is greater than the static array. Normally that would be okay if it was accounted for (calculating everything per unit area) but the article does not seem to be the actual report he made. Shame, that...

The tree design also uses MUCH more area, even though he says it takes less - the tree might have a smaller base, but it casts a much larger shadow which limits your ability to build multip

What strikes me is the surface area taken by the tree versus flat. If I can get 2x as many cells per unit of area in a flat design, would it actually be better?

Follow up experiments would be good. What kind of branch density can you get? How does height affect possible density? As someone pointed out, what if you have all 20 flat cells rotation to point at the sun 24/7.

You caught part of it , but even positioning of the flat array versus his "tree" skewed the results. There were times he shows where the tree was not in shade but the flat panel was fully in shade. The claims of increased efficiency ignore using panels that have mechanisms to allow them to track the sun. Plus he isn't measuring the right output of photo cells, he should have measured energy production.

But now you're talking about optimizations on top of the panels placed on a flat surface.
In this experiment he's comparing "unoptimized" flat panels versus tree-panels which, may I remind you, can be considered to be just as unoptimized as the flat panels. What I'm trying to say is that there are probably a handful of really simple small improvements one can make on the sun panel tree to make it output even more power.

Mod parent up. His testing was flawed. Look at the photo of his "controlled" experiment. Notice how the shadows from a nearby tree are cast onto his experiment. Notice how there are more shadows cast onto his flat array than his artificial tree collelector. He should have placed his experiments out in an open field where the shadows cast from nearby objects would not have interferred.

If you check that image, his tree model was able to pack an increase of 80% cells in 50% of the surface area he placed in the normal flat panel model. The tree model has the advantage that it doesn't have to rotate in order to achieve direct sunlight during the day/year. So it's inventive in his being able to achieve cell density that other people haven't seemly taken advantage of as of yet.

Yes, he's increased the cell density per unit surface area, but he's using all three dimensions, rather than two that the flat arrangement uses (thus more expensive). Cell density per unit volume will have decreased with his model.

Certainly, but it goes to show a linear setup is not always ideal. I would be curious to compare his approach compare to other randomised tree layouts. In many ways what this does is offer tinkerers an other way of looking at things and the chance to validate what he did and maybe even take it in new directions.

If you check that image, his tree model was able to pack an increase of 80% cells in 50% of the surface area he placed in the normal flat panel model. The tree model has the advantage that it doesn't have to rotate in order to achieve direct sunlight during the day/year. So it's inventive in his being able to achieve cell density that other people haven't seemly taken advantage of as of yet.

Actually the idea of 3D solar arrays has been around for a while. The measure of their performance can be total conversion per flat area consumed or the uniformity of their output. The former statistic is only useful when you have a stand-alone case (e.g. one on top of a roof) because they end up shading each other. The other statistic is more useful. If you can use more solar cells but gain more constant energy without moving parts it may be a win because you are collecting more energy per area ov

So presuming for a moment that most of his gains are in fact from the greater variety in orientation compared to the flat panel that only has the single (or two?) orientation(s), then how might this compare to...

A. PV cells with a fixed lens assembly on topB. Flexible PV cells (they tend to flex in only 1 direction), curved so that the entire arc of the sun is perpendicular to the PV's surfaceC. a large array of smaller PV cells on a 2-curve surface

It may be that his 45 mount is like a roof with cells on both 'north-facing' and 'south-facing' slopes, which will lead to one slope being pretty much useless. So his tree arrangement would improve over a flawed arrangement but not over a sensible (and de-facto standard) one.

I understand what was quoted, but it doesn't match what I see. Also, 10 PV cells at 0.5V will have a max voltage of 5V. So how did the tree output 5.25 Volts? Certainly, he had to have more cells on the tree.

If you read the article, he used the same number. Also he explained that though you can use tracking for flat arrays, maintenance costs discourage most people from doing that. So his experiment concluded an improvement for the static array arrangement.

When I read your post and looked at the picture I thought you were right and the young boy was not a smart nerd but a smart manager, politician or lawyer to be. Yet then I went to TFA and looked at the graphs and what he wrote. What the graphs show is voltage and what what he is also talking about is the time at which the energy is produced being 50% longer in case of his model. Now this may or may not be true of course but his observation is about as much about voltage he could get from the device as about

It certainly looks like it from the picture, but he says in the article "The second model was a flat-panel array that was mounted at 45 degrees. It had the same type and number of PV solar panels as the tree design, and the same peak voltage."

You're basing all of your criticism on one picture that may or may not show the actual configuration of his experiment. Knowing photographers, it was probably a posed photo that had nothing to do with the actual experiment.

No, he just compared it to an inefficient distribution (a roof with panels on the south and the north side).

As was pointed out in other comments there are 20 cells on the tree and, most probably, 10 cells on each side of the roof. Had he really compared to 20 cells in a flat panel array, he would have found that the tree distribution is less efficient than the flat panel.

By the way, there is an optimum inclination (vertical angle) of a photovoltaic module, which in Europe is between 30 and 50 (depending on

I think you and most everyone else is missing the larger point of the exercise. It was about learning and applying R & D practices not out smarting the body of engineers with masters and doctorate degrees that have come before him. For a 13 year old to be being taught to do this kind of stuff is impressive and is what inspires, develops and encourages future engineers instead of poorly educated, uninspired, Facialbook social whores. Why is it that every post about a kid doing R & D on/. has to b

How many of you took time at the tender age of 13 to study leaf patterns on trees to figure out how best to capture sunlight and harness it for electricity? You can crap on his science all you want, but kids like this young man inspire me and give me hope that we aren't raising a bunch of video-game addicted sluggards who take everything for granted. Hooray for science and kids who want to pursue it! We want to encourage this behavior, not nit-pick him for possible flaws in research methodology.

It is NOT a power breakthrough - I wish it were. He used a measurement of the open circuit voltage. There is nothing about power in this discussion. A cell may generate very very near peak voltage when angled thirty degrees from the sun, but will produce less than 87% as much power as when faced directly at the sun. Maximizing the duration of the peak voltage is nice, but irrelevant. The integrated power generation is NOT increased with this arrangement.

- He set the flat array at an angle of 45 degrees. Is that the optimum angle for solar panels at his latitude?

- as mentioned elsewhere, more panels in the tree array.

- The photos show both arrays being partly shaded by trees in the yard. Since the arrays aren't at exactly the same position, the amount of shade can be different. The tree array is at an advantage: more distance between the panels means that it's less likely that more than one panel is shaded by a tree branch.

Still, it's an interesting result that raises a few questions:- in current solar panels, the wafers are connected to their beighbors to minimise the amount of wiring. But this means that whole panel drops its output below the threshold if one row of wafers is shaded by a tree branch. Maybe we'd get more energy out of an array if we connected distant wafers in series instead, so a tree branch shadow is less likely to drop the output of a series of wafers below the threshold.

- is it possible to increase the output of an array by putting parts of it at different horizontal or vertical angles?

- is it possible to increase the output of an array by putting parts of it at different horizontal or vertical angles?

In essence, as far as I can figure, yes. The output of a PV cell depends on the irradiance of that cell. The irradiance is strongly linked to the incident angle of the light. This is Lambert's cosine law. In short, the more perpendicular the surface is to the illuminant (the sun), the more energy it will receive.

That's why some solar panels 'track' the sun - so that the panel is perpendi

Two things. One, there is no such thing as a provisional patent. There are provisional patent applications, but provisional patent applications are not separately examined, and patents do not issue from them. They are merely a procedural tool to get yourself an extra year of time to decide whether a patent is worth pursuing on your invention. The only things you need to get yourself a provisional patent application are a specification, a drawing (if applicable), and the filing fee.

If you look at his methodology, it's fundamentally flawed. RTFA and do your own analysis if you want.

During the "peak times" for his model, the flat arrangement was maxed out on production. Lots of lost energy. His "extended time of collection" is the sole basis for his supposed power-collection increases on the tree-like setup.

If you were to do the same experiment with PV cells that didn't max out, you'd find far superior collection from that arrangement. His "power gain" is an artifact of clipping, n

If you look at his methodology, it's fundamentally flawed. RTFA and do your own analysis if you want.

SCIENTIFIC METHODLOGY FAIL

Sorry, but his experiment was NOT to determine a better way of generating solar power, if you RTFA it was an experiment to determine why the leaves on trees are arranged in specific patterns. If you study up a bit about photosynthesis, you'll find it has exactly the same "clipping" issues with regards to energy absorption that a cheap solar panel does. It was a pretty ingenious test to determine the (admittedly obvious) conclusion as to why leaves & branches follow the Fibonacci pattern. He probably should have tried some other tree-like but non-Fibonacci based arrangements, but he does address that point somewhat in his conclusions.

I guess you're saying there is no advantage whatsoever in determining the most efficient arrangement of cheap solar panels? They're common enough devices, so why not arrange them efficiently?

He got modded down because he based his opinion on a photograph which may or may not actually show the experiment. Instead of the article which actually explains that those who are whining about what they see in the photograph are wrong.

While I agree he should have compared angled solar panels (anyone that has done anything with solar knows a panel facing south (in the northern hemisphere) will get more light than a panel laying flat, I think the idea he is going for here is for statically mounted panels such as would go on a building, not for huge solar arrays that have motor guidance etc. Besides, there is a great deal of loss from running the motors, so this could still be more efficient (although a great deal more testing would be need

Rotating the flat panel will enable it to collect many times what the tree can (which rotating does nothing for).

Many plants rotate their leaves to follow the sun (to maximize photosynthesis) and orientate them vertically during the night (in order to shade or protect them during the resting period).
I know this from watching my chilli plants grow. For them this action is more profound when they are young and growing fast. Older plants seem to be much lazier and slower in orienting their leaves. Maybe leaf quantity becomes quality of it's own and following the sun movent accurately becomes unnecessary or wastes more

I've never understood this "buy the patent and bury it" meme. For one thing, if something is patented, it's published. Period. For another, patents expire. We should be neck-deep in 100 MPG carbuerators by now.

He even made the common bar graph mistake (more) of not starting the scale from zero, instead starting from 4v, which makes the 4.1-4.4v flat solar panel appear as if it puts out less than half of the 5.25 volt from the solar tree.